remove test for registering custom excel extensions

Author: tdamsma

pandas/tests/io/test_excel.py

@@ -22,7 +22,7 @@
 from pandas.io.common import URLError
 from pandas.io.excel import (
     ExcelFile, ExcelWriter, _OpenpyxlWriter, _XlsxWriter, _XlwtWriter,
-    read_excel, register_writer)
+    read_excel)
 from pandas.io.formats.excel import ExcelFormatter
 from pandas.io.parsers import read_csv
 
@@ -2350,44 +2350,6 @@ def test_ExcelWriter_dispatch_raises(self):
         with pytest.raises(ValueError, match='No engine'):
             ExcelWriter('nothing')
 
-    @pytest.mark.filterwarnings("ignore:\\nPanel:FutureWarning")
-    def test_register_writer(self):
-        # some awkward mocking to test out dispatch and such actually works
-        called_save = []
-        called_write_cells = []
-
-        class DummyClass(ExcelWriter):
-            called_save = False
-            called_write_cells = False
-            supported_extensions = ['test', 'xlsx', 'xls']
-            engine = 'dummy'
-
-            def save(self):
-                called_save.append(True)
-
-            def write_cells(self, *args, **kwargs):
-                called_write_cells.append(True)
-
-        def check_called(func):
-            func()
-            assert len(called_save) >= 1
-            assert len(called_write_cells) >= 1
-            del called_save[:]
-            del called_write_cells[:]
-
-        with pd.option_context('io.excel.xlsx.writer', 'dummy'):
-            register_writer(DummyClass)
-            writer = ExcelWriter('something.test')
-            assert isinstance(writer, DummyClass)
-            df = tm.makeCustomDataframe(1, 1)
-
-            func = lambda: df.to_excel('something.test')
-            check_called(func)
-            check_called(lambda: df.to_excel('something.xlsx'))
-            check_called(
-                lambda: df.to_excel(
-                    'something.xls', engine='dummy'))
-
 
 @pytest.mark.parametrize('engine', [
     pytest.param('xlwt',